A. Field of the Invention
This invention relates to kickover tools and more particularly to kickover tools for running or retrieving well equipment such as gas lift valves and further relates to a kickover tool which may be used with highly deviated holes without special orientation devices.
B. Prior Art
With the advent of the side pocket mandrel, kickover tools have been utilized for installing and retrieving well equipment such as gas lift valves in the side pocket mandrels.
One form of kickover tool has a centralizing device with outwardly expansible centralizers, such as bow springs, positioned on the tool. (See U.S. Pat. No. 2,679,903, to McGowen, Jr., et al). These tools worked well with mandrels of circular cross-section. However, even though this form of kickover tool has been improved somewhat over the years (See Composite Catalog of Oil Field Equipment and Services, Vol. 24, p. 1102 (1960-1961) and Vol. 29, pp. 1040 and 1041 (1970-1971)), the tool has several deficiencies when used in oval mandrels. All of the tool's outwardly expansible centralizing bow springs are jointly confined at both ends. The bow springs, therefore, all flex together. When well equipment is to be installed or retrieved from a side pocket mandrel with an elliptical or oval cross-section, the tool cannot properly direct a valve into the side pocket. The improper alignment of the tool occurs because the minor axis of the side pocket mandrel will prevent expansion of two of the bow springs. The other spring or springs will also not expand properly because their support is tied to the springs which lie in the minor axis of the mandrel and thus, they cannot flex outward to engage the wall of the side pocket mandrel at its major axis. When the tubing is highly deviated this failure of all the centralizing bow springs to flex outward until they all contact the mandrel wall can be quite disastrous since if the side pocket is located above the axis of the bore of the side pocket mandrel, the kickover tool will be unable to be articulated sufficiently to install or retrieve a valve from the side pocket.
U.S. Pat. No. 2,664,162, discloses individually spring-actuated arms to deflect a kickover tool into the side pocket. The arms do not provide a kickover tool of the centralizing type since only one arm is actuated at a time. In addition, the forces capable of being generated by the disclosed spring system would probably be unable to articulate a kickover tool up into a side pocket above the bore of the mandrel in a highly deviated tubing string.
Some kickover tools, such as the aforementioned tool described in U.S. Pat. No. 2,679,903, utilize a swivel joint to connect the tool to a sub associated with either wire line or pump-down equipment. The swivel joint permits the tool to be kicked over into alignment with the side pocket under the action of the centralizers. However, with a highly deviated string of tubing and with the side pocket located below the axis of the side pocket mandrel bore, the force of gravity could cause the tool to pivot about the swivel joint and unintentionally fall into the side pocket.
U.S. Pat. No. 3,828,853 discloses the utilization of a sleeve to telescope over the swivel joint while the tool is being run in the tubing to maintain the tool in alignment with the connecting sub.